int(request.REQUEST.get('index', 0) all in try/except. See #9918

Can't assume that request strings are castable to int().
getIntOrDefault(request,name,default) helper. See #9918, PR482
Only add index to editinline urls if {{ index }} in context. See #9918

This is a further measure to prevent invalid ?index= urls to cause errors in parsing request.get('index')
getIntOrDefault() 'print' and ValueError fixes
Merge pull request #603 from will-moore/9918_tag_edit

9918 tag edit develop